Delayed cancel call waiting
CA 2085280 C · Owner: Mitel Knowledge Corporation · Inventors: Quirk, Carole
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A telecommunications system with a call waiting feature comprises a central office and a plurality of subscribers. The system includes an arrangement for transmitting a signal over an off-hook line to alert the subscriber to the presence of an incoming call, and a cancel call waiting (CCW) register at said central office. The CCW register is associated with each subscriber line and is set to cancel the call waiting feature in response to receipt of a cancellation code over the associated subscriber line and is reset upon termination of a subsequent call. The central office further comprises a delayed cancel call waiting (DCCW) register for each subscriber line with at least a first state …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 14, 1992 and granted August 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.